require(File.dirname(__FILE__)+'/helpers_tests.rb')

class StatsampleTestTTestCase < MiniTest::Unit::TestCase
  include Statsample::Test
  include Math
  context T do 
    setup do
      @a=[30.02, 29.99, 30.11, 29.97, 30.01, 29.99].to_scale
      @b=[29.89, 29.93, 29.72, 29.98, 30.02, 29.98].to_scale
      @x1=@a.mean
      @x2=@b.mean
      @s1=@a.sd
      @s2=@b.sd
      @n1=@a.n
      @n2=@b.n
    end
    should "calculate correctly t for two samples" do
      assert_in_delta(1.959, T.two_sample_independent(@x1, @x2, @s1, @s2, @n1, @n2),0.001)
      assert_in_delta(1.959, T.two_sample_independent(@x1, @x2, @s1, @s2, @n1, @n2,true),0.001)
    end
    should "calculate correctly df for equal and unequal variance" do
      assert_equal(10,  T.df_equal_variance(@n1,@n2))
      assert_in_delta(7.03,  T.df_not_equal_variance(@s1,@s2,@n1,@n2),0.001)    
    end
    should "calculate all values for T object" do
      t=Statsample::Test.t_two_samples_independent(@a,@b)
      assert(t.summary.size>0)
      assert_in_delta(1.959, t.t_equal_variance,0.001)
      assert_in_delta(1.959, t.t_not_equal_variance,0.001)
      assert_in_delta(10, t.df_equal_variance,0.001)
      assert_in_delta(7.03, t.df_not_equal_variance,0.001)
      assert_in_delta(0.07856, t.probability_equal_variance,0.001)
      assert_in_delta(0.09095, t.probability_not_equal_variance,0.001)
    end
    should "be the same using shorthand" do
      v=100.times.map {rand(100)}.to_scale
      assert_equal(Statsample::Test.t_one_sample(v).t, T::OneSample.new(v).t)
    end
    should "calculate all values for one sample T test" do
      u=@a.mean+(1-rand*2)
      tos=T::OneSample.new(@a,{:u=>u})
      assert_equal((@a.mean-u).quo(@a.sd.quo(sqrt(@a.n))), tos.t)
      assert_equal(@a.n-1, tos.df)
      assert(tos.summary.size>0)
    end
  end
end
